Method of restoring effectiveness of deteriorated rivets



A ril 10, 1934., A.-G.J LEAK E 4,

METHOD OFR ESTORING EFFECTIVENESS OF DETERIQRATED RIVETS I Filed Dec. 30, 19551 '14 IIIIIIIIIIIIIII'IA Maya Patented Apr. 10, 1934 PATENT OFFICE METHOD OF RESTORING EFFECTIVENESS OF DETERIORATED RIVETS Arthur G. Leake, Bridgeport, Conn.

Application December 30, 1931, Serial No. 583,814

' 2 Claims. (01. 29-150) This invention relates to structural structures comprising structural members secured together by rivets, and more particularly to a method and means of restoring the efiectiveness of 'deteriorated rivets.

It is an object of the invention toprovide an improved method .and means of restoring the effectiveness of deteriorated rivets without tearing down the structure, and which may be used while it is in position and even while it is under load.

It is also an object of the invention to provide amethod andmeans which may be used to' restore the effectiveness of the deteriorated rivets but may also be used in conjunction with a strengthening member to increase the sec,-

tion of the built-up members, and therefore to increase their strength and increase their load carrying capacity without disturbing the structure, and therefore may be applied while it is in position.

With the foregoing and other objects in view, the invention consists in an improved method and means of restoring defective rivets by restoring with weld metal, as will be more fully disclosed in connection with the accompanying drawing.

In this drawing:

Fig. 1 is 'a side elevation with a portion of a built-up beam or girder showing the application of my invention;

Fig. 2 is a vertical section thereof substantially on line 2-2 of Fig. 1;

Fig. 3 is a top plan view thereof; and

Fig. 4 is an enlarged section substantially on line 44 of Fig. 3.

In the drawing the invention is shown as applied to a built-up beam or girder comprising a web plate 10 and. angle members 11 riveted to the upper and lower edges thereof by rivets 12. To the horizontal flanges are riveted longitudinal plates 13 by means of rivets 14. It is, however, to be understood that this particular structure is shown merely for illustration and that the invention is equally applicable to restoring deteriorated rivets in other structures, such as platesybars, channels, beams, trusses, columns,

chords for trusses, webs or plate girders, and

all types of built-up structures.

In describing the invention we will assume that the outer heads of the rivets 14 have deteriorated. These heads indicated by dotted line 14a Fig. 4, are all cut off and preferably the shank 15 is also cut down below the surface of the member 13 a suitable distance, preferably about an eighth of an inch, this distance of coursedepending upon the condition of therivet, its size, etc., and some of the metal of plate 13 around the end of the rivet shank may also be removed if desired. This portion of the rivet may be removed by cutting, burning, or other suitable means, and then the shank is welded to the structural meinber flush with the surface thereof as indicated at 16. In welding this stub or shank of the rivetto the old plate, the metal is welded on'the outer circumference of the shank or the rivet and simultaneously to'the old plate penetrating' to the structural member sufficiently to give a good strong bond. It has been shown by tests that where these rivets are either in shear,

tension or compression, my method is feasible and safe and that by removing the rivet head and welding the shank to the structuralv member flush withthe surface as described, the strength of the rivet is restored and the actual value 76 of the rivet head has not decreased. This can be applied while the structure is in position and eliminates the necessity of the removal and replacement of rivets. It also removes the necessity of shoring, blocking up or otherwise support- 80 ing the member during the repairing operation as the heads of the rivets may be removed one at a time and welded up'fiu'sh to restore its full value. This method therefore presents an efficient and safe method of repairing structural members under load at a much reduced cost over the old methods.

' Where it is necessary or desirable to add structural shapes to increase the section, and therefore increase the strength of the built-up struc- 0o ture, this method removes the old rivet heads which protruded so as to interfere with the application of new shapes or strengthening members. After the rivets have been restored as described and welded up flush as indicated, then the new strengthening member or any desired shape, such as the plate-17 or 18 can be applied and welded in position. If the plate is narrower than the old plate 13, such as is shown for the plate 17, then the edges of this plate can be welded to the surface of the old plate 13 as indicated at- 19, the welding preferably being done by electric welding and the addition of metal from the welding rod. If the strengthening plate is of greater width than the plate 13 then the edges of the plate 13 can be welded in a similar manner to the surfaces of the plate 18 as indicated at 20. This method and means of strengthening the structures can be used in conjunction with the method disclosed in my prior Patents 11o Nos. 1,770,932 and 1,770,933 for Method of strengthening structural members under load issued July 22, 1930, although of course it is not limited thereto. 1

Having thus set forth the nature of my invention, what I claim is:

l. The method of restoring the efiectiveness of deteriorated rivets in structural members and reinforcing said members which comprises removing the deteriorated rivet heads and parts of the shanks to a distance below the surface of the structural member, then welding the peripheries of the shanks to the member and building up the ends of the shanks with weld metal to a level flush with the surface of themember, placing a reinforcing structural member over the built-up end of the rivets and welding to the structural member.

2. The method of restoring the efiectiveness of deteriorated rivets in structural members while under load which comprises removing the deteriorated head of the rivet and a. part of the shank to a distance below the surface of the member without removing the rivet, welding the shank to the member and building up the shank with weld metal to a level flush with the surface of the member, and welding a reinforcing member to the old member over the built up ends of the rivets.

ARTHUR. G. LEAKE. 

